Tamed fox shows domestication's effects on the brain

[RainDog]

10. they selected by phenotype, not genotype

the expression of genes, rather than genes themselves, were the focus of the study because, really, there is no one single gene that explains most any behavior. Genes live in communities, just as humans do, and their expressions are influenced by their communities.

what the study indicates, it seems to me, is that, amazingly, in only 50 years, a major behavioral change was bred, in two different directions.

Within one lifetime, iow, domestication of a species may have been accomplished by an observant group or groups of humans.

This might also be considered a behavioral sort of "founder effect" - a small population breeds among itself and particular traits arise from that small population. These foxes could still interbreed, but the basis of the founder effect as an issue in biology is a change in gene expression because of a small population that, eventually, is geographically isolated, etc. and, even more eventually, creates a new species.